1. Field of the Invention
The present invention relates generally to a piezoelectric identification device and applications thereof.
2. Background Art
Biometrics are a group of technologies that provide a high level of security. Fingerprint capture and recognition is an important biometric technology. Law enforcement, banking, voting, and other industries increasingly rely upon fingerprints as a biometric to recognize or verify identity. See, Biometrics Explained, v. 2.0, G. Roethenbaugh, International Computer Society Assn. Carlisle, Pa. 1998, pages 1-34 (incorporated herein by reference in its entirety).
Optical fingerprint scanners are available which detect a reflected optical image of a fingerprint. To capture a quality image at a sufficiently high resolution, optical fingerprint scanners require at minimum optical components (e.g., lenses), an illumination source, and an imaging camera. Such components add to the overall cost of a fingerprint scanner. Mechanical structures to maintain alignment also increase manufacturing and maintenance costs.
Solid-state silicon-based transducers are also available in fingerprint scanners sold commercially. Such silicon transducers measure capacitance. This requires the brittle silicon transducers to be within a few microns of the fingerprint sensing circuit reducing their durability. To detect a rolled fingerprint, the sensing array of the solid-state transducer needs to have an area of 1 inch.times.1 inch and a thickness of about 50 microns. This is a big geometry for silicon that increases the base cost of a fingerprint scanner and leads to greater maintenance costs. Durability and structural integrity are also more likely to suffer in such a large silicon geometry.
What is needed is an inexpensive, durable fingerprint scanner with low maintenance costs. What is also needed is a low cost biometric device that can protect the individuals and the general populace against physical danger, fraud, and theft (especially in the realm of electronic commerce).